Nelson Mandela was hospitalized Saturday in South Africa for what was called a “scheduled medical check-up.” It was the second time in three months that the country’s former president was hospitalized.

Mandela was admitted to the hospital “for a scheduled medical check-up to manage existing conditions in line with his age,” presidential spokesman Mac Maharaj told NBC News. “Doctors are conducting tests and have thus far indicated that there is no reason for any alarm.”

The government did not reveal other details about the prominent anti-apartheid leader’s treatment in a Pretoria hospital on Saturday.

Mandela spent nearly three weeks in the hospital in December for treatment of a lung infection and gallstone surgery. The leader’s December hospitalization was his longest since being released from captivity as a political prisoner in 1990.